Mr. Cooper has long been regarded as the strongest host at CNN… For the quarter, Mr. Cooper dropped 42 per cent in viewers and 46 per cent among the 25-to-54-year-old audience that the news channels use for their sales to advertisers.

In the past, CNN relied on big audiences for Mr. King’s show to deliver viewers to Mr. Cooper. Now Mr. Cooper sometimes finds himself losing to repeats of shows on MSNBC and HLN. (At the other end of prime time, Campbell Brown‘s show on CNN at 8 had its worst quarter ever with the 25-to-54-year-old audience.)

Mr. King’s audience dropped 43 per cent for the quarter and 52 per cent in March. He dropped to 771,000 viewers for the quarter from 1.34 million in 2009. More alarming perhaps, Mr. King, whose show has been regularly eclipsed by Rachel Maddow‘s on MSNBC (and is almost quadrupled by Sean Hannity‘s show on Fox), is now threatened by a new host, Joy Behar on HLN (formerly Headline News.)

In her first full quarter competing with Mr. King at 9 p.m. Ms. Behar wound up beating him in the ratings 21 times.

We get that CNN wants to stick to its knitting. But how much is enough?